A piano teacher tracks the number of audience members for a recital to plan the best size auditorium to reserve for future recitals. The model ŷ = 3.5x + 8.9 explains the relationship between x, the number of students performing, and ŷ, the predicted number of audience members. Identify and interpret the y-intercept.

The y-intercept is 8.9. For every additional student performing, the audience is predicted to grow by 8.9 people.
The y-intercept is 8.9. When no students are performing, 8.9 people are predicted to be in the audience.
The y-intercept is 3.5. For every additional student performing, the audience is predicted to grow by 3.5 people.
The y-intercept is 3.5. When no students are performing, 3.5 people are predicted to be in the audience.